US Patent 11176308 Extracting parasitic capacitance from circuit designs

An integrated circuit includes a target wiring layer, a first adjacent wiring layer above the target wiring layer, and a second adjacent wiring layer below the target wiring layer. Each adjacent wiring layer including crossing wires orthogonal to the target wiring layer. Modify a putative design of the integrated circuit by selecting a target wire; identifying lateral neighbors of the target wire; defining regions of the target wire where the lateral neighbors are homogeneous in cross-section; for each region of the target wire, calculating a wire pattern for the crossing wires; identifying segments within above and below portions of the wire pattern; for each above and below segment pair, obtaining a per-unit-length capacitance from a reduced pattern database; extracting a total parasitic capacitance from the per-unit-length pattern capacitances; and in response to an assessment of the impact of the total parasitic capacitance on circuit performance, producing a modified design.